1// SPDX-License-Identifier: GPL-2.0
2/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
3 *
4 * Authors:
5 * Alexander Aring <aar@pengutronix.de>
6 * Eric Anholt <eric@anholt.net>
7 */
8
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/platform_device.h>
12#include <linux/pm_domain.h>
13#include <dt-bindings/power/raspberrypi-power.h>
14#include <soc/bcm2835/raspberrypi-firmware.h>
15
16/*
17 * Firmware indices for the old power domains interface.  Only a few
18 * of them were actually implemented.
19 */
20#define RPI_OLD_POWER_DOMAIN_USB		3
21#define RPI_OLD_POWER_DOMAIN_V3D		10
22
23struct rpi_power_domain {
24	u32 domain;
25	bool enabled;
26	bool old_interface;
27	struct generic_pm_domain base;
28	struct rpi_firmware *fw;
29};
30
31struct rpi_power_domains {
32	bool has_new_interface;
33	struct genpd_onecell_data xlate;
34	struct rpi_firmware *fw;
35	struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
36};
37
38/*
39 * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
40 * RPI_FIRMWARE_SET_DOMAIN_STATE
41 */
42struct rpi_power_domain_packet {
43	u32 domain;
44	u32 on;
45};
46
47/*
48 * Asks the firmware to enable or disable power on a specific power
49 * domain.
50 */
51static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
52{
53	struct rpi_power_domain_packet packet;
54
55	packet.domain = rpi_domain->domain;
56	packet.on = on;
57	return rpi_firmware_property(rpi_domain->fw,
58				     rpi_domain->old_interface ?
59				     RPI_FIRMWARE_SET_POWER_STATE :
60				     RPI_FIRMWARE_SET_DOMAIN_STATE,
61				     &packet, sizeof(packet));
62}
63
64static int rpi_domain_off(struct generic_pm_domain *domain)
65{
66	struct rpi_power_domain *rpi_domain =
67		container_of(domain, struct rpi_power_domain, base);
68
69	return rpi_firmware_set_power(rpi_domain, false);
70}
71
72static int rpi_domain_on(struct generic_pm_domain *domain)
73{
74	struct rpi_power_domain *rpi_domain =
75		container_of(domain, struct rpi_power_domain, base);
76
77	return rpi_firmware_set_power(rpi_domain, true);
78}
79
80static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
81					 int xlate_index, const char *name)
82{
83	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
84
85	dom->fw = rpi_domains->fw;
86
87	dom->base.name = name;
88	dom->base.power_on = rpi_domain_on;
89	dom->base.power_off = rpi_domain_off;
90
91	/*
92	 * Treat all power domains as off at boot.
93	 *
94	 * The firmware itself may be keeping some domains on, but
95	 * from Linux's perspective all we control is the refcounts
96	 * that we give to the firmware, and we can't ask the firmware
97	 * to turn off something that we haven't ourselves turned on.
98	 */
99	pm_genpd_init(&dom->base, NULL, true);
100
101	rpi_domains->xlate.domains[xlate_index] = &dom->base;
102}
103
104static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
105				  int xlate_index, const char *name)
106{
107	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
108
109	if (!rpi_domains->has_new_interface)
110		return;
111
112	/* The DT binding index is the firmware's domain index minus one. */
113	dom->domain = xlate_index + 1;
114
115	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
116}
117
118static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
119				      int xlate_index, int domain,
120				      const char *name)
121{
122	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
123
124	dom->old_interface = true;
125	dom->domain = domain;
126
127	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
128}
129
130/*
131 * Detects whether the firmware supports the new power domains interface.
132 *
133 * The firmware doesn't actually return an error on an unknown tag,
134 * and just skips over it, so we do the detection by putting an
135 * unexpected value in the return field and checking if it was
136 * unchanged.
137 */
138static bool
139rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
140{
141	struct rpi_power_domain_packet packet;
142	int ret;
143
144	packet.domain = RPI_POWER_DOMAIN_ARM;
145	packet.on = ~0;
146
147	ret = rpi_firmware_property(rpi_domains->fw,
148				    RPI_FIRMWARE_GET_DOMAIN_STATE,
149				    &packet, sizeof(packet));
150
151	return ret == 0 && packet.on != ~0;
152}
153
154static int rpi_power_probe(struct platform_device *pdev)
155{
156	struct device_node *fw_np;
157	struct device *dev = &pdev->dev;
158	struct rpi_power_domains *rpi_domains;
159
160	rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
161	if (!rpi_domains)
162		return -ENOMEM;
163
164	rpi_domains->xlate.domains =
165		devm_kcalloc(dev,
166			     RPI_POWER_DOMAIN_COUNT,
167			     sizeof(*rpi_domains->xlate.domains),
168			     GFP_KERNEL);
169	if (!rpi_domains->xlate.domains)
170		return -ENOMEM;
171
172	rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
173
174	fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
175	if (!fw_np) {
176		dev_err(&pdev->dev, "no firmware node\n");
177		return -ENODEV;
178	}
179
180	rpi_domains->fw = devm_rpi_firmware_get(&pdev->dev, fw_np);
181	of_node_put(fw_np);
182	if (!rpi_domains->fw)
183		return -EPROBE_DEFER;
184
185	rpi_domains->has_new_interface =
186		rpi_has_new_domain_support(rpi_domains);
187
188	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
189	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
190	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
191	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
192			      "VIDEO_SCALER");
193	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
194	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
195
196	/*
197	 * Use the old firmware interface for USB power, so that we
198	 * can turn it on even if the firmware hasn't been updated.
199	 */
200	rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
201				  RPI_OLD_POWER_DOMAIN_USB, "USB");
202
203	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
204	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
205	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
206	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
207	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
208	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
209	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
210	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
211	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
212	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
213	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
214	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
215	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
216			      "TRANSPOSER");
217	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
218	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
219	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
220
221	of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
222
223	platform_set_drvdata(pdev, rpi_domains);
224
225	return 0;
226}
227
228static const struct of_device_id rpi_power_of_match[] = {
229	{ .compatible = "raspberrypi,bcm2835-power", },
230	{},
231};
232MODULE_DEVICE_TABLE(of, rpi_power_of_match);
233
234static struct platform_driver rpi_power_driver = {
235	.driver = {
236		.name = "raspberrypi-power",
237		.of_match_table = rpi_power_of_match,
238	},
239	.probe		= rpi_power_probe,
240};
241builtin_platform_driver(rpi_power_driver);
242
243MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
244MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
245MODULE_DESCRIPTION("Raspberry Pi power domain driver");
246